Anti-Rab3 GDP-GTP exchange factor antibodies are used in antigen-specific immunodetection in biological samples. The target Rab3 GDP-GTP exchange factor is a known alias name of the protein MAP kinase activating death domain, encoded by the MADD gene in humans. This 1647-amino acid residue protein is known to be involved in receptor-mediated signaling pathways and the apoptotic pathway, among other biological processes. It is localized to the cell membrane and cytoplasm of the cell. In terms of tissue expression, it is reported to be expressed in the testis, ovary, brain and heart.